Hybrid approach of discrete event simulation integrated with location search algorithm in a cells assignment problem: a case study

[EN] This paper presents a case study describing a cell assignment problem in an assembly facility. These cells receive parts from external suppliers, and sort and sequence these parts to feed the final assembly line. Therefore, to each cell are associated important inbound and outbound flows generating hundreds of material handling equipment movements along the facility, impacting the traffic density and causing eventually safety issues in the plant. Following an important plant redesign, cells have been relocated, and the plant managers need to decide how to manage the new logistic flows. To that aim, a hybrid approach encompassing mathematical optimization and discrete event simulation (DES) is proposed. This approach allows us to reduce complexity by decomposing the design into two phases. The first phase deals with the problem of generating cell¿s assignment alternatives by using a heuristic method to find good quality solutions. Then, a DES software is used to dynamically evaluate the performance of the solutions with respect to operational features such as traffic congestion and intensity. This second phase provides interesting managerial insights on the manufacturing system from both quantitative and qualitative aspects related to in-plant safety and traffic.Saez-Mas, A.; García Sabater, JJ.; García Sabater, JP.; Maheut, J. (2020). Hybrid approach of discrete event simulation integrated with location search algorithm in a cells assignment problem: a case study. Central European Journal of Operations Research. 28(1):125-142. https://doi.org/10.1007/s10100-018-0548-5S125142281Anjos MF, Vieira MVC (2017) Mathematical optimization approaches for facility layout problems: the state-of-the-art and future research directions. Eur J Oper Res 261(1):1–16. https://doi.org/10.1016/j.ejor.2017.01.049Battini D, Boysen N, Emde S (2013) Just-in-time supermarkets for part supply in the automobile industry. J Manag Control 24(2):209–217. https://doi.org/10.1007/s00187-012-0154-yBenjaafar S (2002) Modeling and analysis of congestion in the design of facility layouts. Manag Sci 48(5):679–704. https://doi.org/10.1287/mnsc.48.5.679.7800Board TR (2010) Highway capacity manual. Environmental ProtectionBoysen N, Emde S, Hoeck M, Kauderer M (2015) Part logistics in the automotive industry: decision problems, literature review and research agenda. Eur J Oper Res 242(1):107–120. https://doi.org/10.1016/j.ejor.2014.09.065Caputo AC, Pelagagge PM, Salini P (2015) Modeling errors in kitting processes for assembly lines feeding. IFAC Proc Vol (IFAC PapersOnline) 48(3):338–344. https://doi.org/10.1016/j.ifacol.2015.06.104Centobelli P, Cerchione R, Murino T (2016) Layout and material flow optimization in digital factory. Int J Simul Model 15(2):223–235. https://doi.org/10.2507/IJSIMM15(2)3.327Dehghanimohammadabadi M, Keyser TK (2017) Intelligent simulation: integration of SIMIO and MATLAB to deploy decision support systems to simulation environment. Simul Model Pract Theory 71:45–60. https://doi.org/10.1016/j.simpat.2016.08.007Ficko M, Palcic I (2013) Designing a layout using the modified triangle method, and genetic algorithms. Int J Simul Model 12(4):237–251. https://doi.org/10.2507/IJSIMM12(4)3.244Gamberi M, Manzini R, Regattieri A (2009) An new approach for the automatic analysis and control of material handling systems: integrated layout flow analysis (ILFA). Int J Adv Manuf Technol 41(1–2):156–167. https://doi.org/10.1007/s00170-008-1466-9Gould O, Colwill J (2015) A framework for material flow assessment in manufacturing systems. J Ind Prod Eng 32(1):55–66. https://doi.org/10.1080/21681015.2014.1000403Hasda RK, Bhattacharjya RK, Bennis F (2016) Modified genetic algorithms for solving facility layout problems. Int J Interact Des Manuf (IJIDeM) 11(3):1–13. https://doi.org/10.1007/s12008-016-0362-zImran M, Kang C, Hae Lee Y, Zaib J, Aziz H (2017) Cell formation in a cellular manufacturing system using simulation integrated hybrid genetic algorithm. Comput Ind Eng 105:123–135. https://doi.org/10.1016/j.cie.2016.12.028Iqbal M, Hashmi MSJ (2001) Design and analysis of a virtual factory layout. J Mater Process Technol 118(1–3):403–410. https://doi.org/10.1016/S0924-0136(01)00908-6Jainury SM, Ramli R, Ab Rahman MN, Omar A (2014) Integrated Set Parts Supply system in a mixed-model assembly line. Comput Ind Eng 75(1):266–273. https://doi.org/10.1016/j.cie.2014.07.008Kanduc T, Rodic B (2016) Optimisation of machine layout using a force generated graph algorithm and simulated annealing. Int J Simul Model 15(2):275–287. https://doi.org/10.2507/IJSIMM15(2)7.335Kang J (2001) A new trend of parts supply system in Korean automobile industry; the case of the modular production system at Hyundai Motor Company. In: Proceedings of the fifth Russian-Korean international symposium on science and technology, 2001. KORUS '01. IEEE, Tomsk, Russia, Russia. https://doi.org/10.1109/KORUS.2001.975268Kim J, Yu G, Jang YJ (2016) Semiconductor FAB layout design analysis with 300-mm FAB data: “is minimum distance-based layout design best for semiconductor FAB design?”. Comput Ind Eng 99:330–346. https://doi.org/10.1016/j.cie.2016.02.012Krishnan KK, Jithavech I, Liao H (2009) Mitigation of risk in facility layout design for single and multi-period problems. Int J Prod Res 47(21):5911–5940. https://doi.org/10.1080/00207540802175337Ku M-Y, Hu MH, Wang M-J (2011) Simulated annealing based parallel genetic algorithm for facility layout problem. Int J Prod Res 49(6):1801–1812. https://doi.org/10.1080/00207541003645789Kulturel-Konak S (2017) A matheuristic approach for solving the dynamic facility layout a matheuristic approach for problem solving the dynamic facility layout problem. Proc Comput Sci 108(June):1374–1383. https://doi.org/10.1016/j.procs.2017.05.234Leveson N (2004) A new accident model for engineering safer systems. Saf Sci 42(4):237–270. https://doi.org/10.1016/S0925-7535(03)00047-XNegahban A, Smith JS (2014) Simulation for manufacturing system design and operation: literature review and analysis. J Manuf Syst 33(2):241–261. https://doi.org/10.1016/j.jmsy.2013.12.007Prajapat N, Tiwari A (2017) A review of assembly optimisation applications using discrete event simulation. Int J Comput Integr Manuf 30(2–3):215–228. https://doi.org/10.1080/0951192X.2016.1145812Saez-Mas A, Garcia-Sabater JP, Morant-Llorca J (2018) Using 4-layer architecture to simulate product and information flows in manufacturing. Int J Simul Model 17(1):30–41. https://doi.org/10.2507/IJSIMM17(1)408Seebacher G, Winkler H, Oberegger B (2015) In-plant logistics efficiency valuation using discrete event simulation. Int J Simul Model 14:60–70. https://doi.org/10.2507/IJSIMM14(1)6.289Singh RR, Sharma SPK (2006) A review of different approaches to the facility layout problems. Int J Adv Manuf Technol 30(5–6):425–433. https://doi.org/10.1007/s00170-005-0087-9Tompkins J, White J, Bozer Y, Tanchoco J (2003) Facilities planning. Wiley, New YorkTugnoli A, Khan F, Amyotte P, Cozzani V (2008) Safety assessment in plant layout design using indexing approach: implementing inherent safety perspective. Part 1—guideword applicability and method description. J Hazard Mater 160(1):100–109. https://doi.org/10.1016/j.jhazmat.2008.02.089Zhang M, Batta R, Nagi R (2009) Modeling of workflow congestion and optimization of flow routing in a manufacturing/warehouse facility. Manag Sci 55(2):267–280. https://doi.org/10.1287/mnsc.1080.0916Zhou F, AbouRizk SM, AL-Battaineh H (2009) Optimisation of construction site layout using a hybrid simulation-based system. Simul Model Pract Theory 17(2):348–363. https://doi.org/10.1016/j.simpat.2008.09.011Zhuo L, Chua Kim Huat D, Wee KH (2012) Scheduling dynamic block assembly in shipbuilding through hybrid simulation and spatial optimisation. Int J Prod Res 50(20):5986–6004. https://doi.org/10.1080/00207543.2011.639816Zupan H, Herakovic N, Starbek M (2016) hybrid algorithm based on priority rules for simulation of workshop production. Int J Simul Model 15(1):29–41. https://doi.org/10.2507/IJSIMM15(1)3.31

Oscillation tomografy study of Earth's composition and density with atmospheric neutrinos

Knowledge of the composition of the Earth's interior is highly relevant to many geophysical and geochemical problems. Neutrino oscillations are modified in a non-trivial way by the matter effects and can provide valuable and unique information not only on the density but also on the chemical and isotopic composition of the deep regions of the planet. In this paper, we re-examine the possibility of performing an oscillation tomography of the Earth with atmospheric neutrinos and antineutrinos to obtain information on the composition and density of the outer core and the mantle, complementary to that obtained by geophysical methods. Particular attention is paid to the D$^{\prime \prime}$ layer just above the core-mantle boundary and to the water (hydrogen) content in the mantle transition zone. Our analysis is based on a Monte-Carlo simulation of the energy and azimuthal angle distribution of $\mu$-like events generated by neutrinos. Taking as reference a model of the Earth consisting of 55 concentric layers with constant densities determined from the PREM, we evaluate the effect on the number of events due to changes in the composition and density of the outer core and the mantle. To examine the capacity of a detector like ORCA to resolve such variations, we construct regions in planes of two of these quantities where the statistical significance of the discrepancies between the reference and the modified Earth are less than $1\sigma$. The variations are implemented in such a way that the constraint imposed by both the total mass of the Earth and its moment of inertia are verified.Comment: Already published in the European Physical Journal

El estreñimiento infantil, una visión desde la farmacia comunitaria

El estreñimiento en los niños es una de las consultas frecuentes en la farmacia comunitaria. Las precauciones básicas en la alimentación del lactante y el conocimiento de las pautas apropiadas en la introducción de nuevos alimentos se relacionan con la maduración progresiva de los sistemas digestivo y metabólico. El estreñimiento infantil se acompaña de una serie de síntomas cuya trascendencia es necesario reconocer y valorar con el fin de recomendar la consulta al médico o realizar la indicación farmacéutica correspondiente. Las papillas existentes en el mercado español pueden resultar útiles para mejorar el estreñimiento infantil, ya que aportan más fibra, disminuyendo la consistencia de las heces y también ejerciendo un efecto prebiótico (añadiendo FOS e inulina). Otras aportan fibra alimentaria, añadiendo mayor cantidad de pulpas de fruta. La educación dirigida a las madres en cuanto a hábitos alimentarios y una adecuada elección de los productos dietéticos indicados en esta situación permiten, en muchas ocasiones, resolver el problema sin necesidad de recurrir a tratamientos farmacológicos, no siempre conveniente

Automatic generation of digital twin industrial system from a high level specification

A framework for the generation of industrial digital twins is presented in the paper. The framework supports industry automated systems preliminary design development, but also supports the following detailed designs implementation and final systems exploitation phases. The main problem is that requirements for first development phases are much more generic than those required for the later phases. The framework faces this problem by avoiding too detailed specifications for the digital twin generated software, but, at the same time, it takes advantage of the specific applications developed for each industrial implementation where that specificities are taken into account: the final control application and the management application. By properly linking both: the more generic digital twin and specific software applications specifically generated for the industry system, the framework may be ready to be used soon at the early development stages, but also may be used for detailed analyses at late booting and maintenance industry system phases. The system has been specialized in industrial transportation and warehouse systems. The paper presents an example of application for this kind of system

Darbepoetin Versus Epoetin Alfa for the Correction of Anemia in Cancer Patients Receiving Radiotherapy or Chemoradiotherapy Treatment

Introduction Anemia is the most frequent hematological disturbance in cancer patients, with prevalence between 30% and 90%, depending on the type of tumor, the antitumor treatment, and other factors (infection, malnutrition, bleeding, tumor infiltration of the bone marrow). A number of erythropoietic agents have shown to be effective in increasing the hemoglobin (Hb) levels, reducing the requirements for transfusion, and improving quality of life. The objective of this study is to compare darbepoetin alfa and epoetin alfa when used to correct anemia in cancer patients who are receiving radiotherapy or radiochemotherapy. Material and methods A prospective study of 125 consecutive patients with anemia (Hb < 13 g/dL in males or < 12 g/dL in females) who were undergoing treatment with radiotherapy (RT) or radiochemotherapy (RCT) in our department were enrolled between March 2003 and March 2005. The treatment for the anemia was either darbepoetin alfa 150 mcg/week (62 patients, group 1) or epoetin alfa 40,000 IU/week (63 patients, group 2). Patients received iron supplements in both groups. Treatment was administered in a consecutive manner depending on tumor type. If the increase in Hb was < 1 g/dL after 4 weeks of treatment, the dose was increased to 300 mcg/week in group 1 or to 60,000 IU/week in group 2. The treatment was terminated when a Hb value of ≥ 15 g/dL was reached during RT treatment, a Hb value of ≥ 14 g/dL was reached if the RT had been completed, or after 16 weeks of treatment whatever the Hb value. The mean age of patients was 63.36 ± 11.27 years, 67% were male. No significant differences were observed between the 2 groups in tumor type or stage, previous treatments, or intent to treat with RT or RCT. Results Comparing group 1 and group 2 by intent to treat, the mean Hb at the start of treatment with the study drug was 12.1 g/dL vs 11.8 g/dL, the proportion of patients whose dose was increased was19.7% vs 24.6%, the need for transfusion was 3.2% in each group, the duration of erythropoietic treatment was 6.5 weeks in both groups, and 2 patients in group 2 restarted treatment with epoetin alfa. The percentage of patients who responded (defined as an increase in the Hb ≥ 2 g/dL in the absence of transfusions) was of 72.6% and 66.7%, respectively. Four vascular adverse events were observed, 2 in each group. No significant differences were observed with respect to the baseline, week 4, and week 12 levels of endogenous erythropoietin, serum iron,% saturation, and ferritin. The increase in Hb 1 month after the final administration of the study drug was 2.21 g/dL in group 1 and 2.46 g/dL in group 2 (p = ns). Conclusions The results of our study demonstrate that both treatments are equally effective in correcting anemia in cancer patients undergoing RT or RCT

La naturaleza en la Eneida: Función simbólica y poética

El poema épico de la Eneida presenta una excepcional riqueza de motivos ligados a la naturaleza. La ausencia de un estudio de conjunto acerca de este tema justifica la realización del presente trabajo que comprende el análisis de todos los pasajes (185 en total) con motivos naturalistas, en cualquiera de sus formas de aparición: écfrasis, símiles, prodigios-augurios, metamorfosis, exempla. El estudio está articulado en torno a grandes bloques temáticos. En todos ellos se comprueba que Virgilio actúa siguiendo las concepciones propias del contexto cultural y de la propaganda augústea: la tempestad expresa el caos cósmico, político, social y personal; la vegetación, las preocupaciones dinásticas, en especial, a través de ritual del Rex Nemorensis; la Arcadia, el ideal de una era de prosperidad y paz; la montaña tiene un significado polivalente asociado a la divinidad y las dificultades, mientras la caverna se liga al caos y el Mal; el día sirve para establecer un paralelismo entre Augusto y Camilo; los animales, según sus cualidades, representan los dos ejes de la oposición entre caos y cosmos (hybris y diké).Desde el punto de vista metapoético, la naturaleza sirve para plasmar un diálogo entre el autor y su propia obra en el que podemos ver el proceso creativo del autor reflejado en distintas metáforas del texto: el barco y la navegación, el árbol o el camino. La conclusión es que la naturaleza contribuye a plasmar el pensamiento de los protagonistas (o del autor) y caracterizarlos o para anticipar los acontecimientos. Virgilio modifica el paisaje combinando realidad e imaginación para adaptarlo a sus propios fines. <br /

Cambios en la vegetación durante el Holoceno reciente en el valle de Lozoya (Sierra de Guadarrama, Madrid)

Se presentan los datos palinológicos procedentes de un testigo obtenido en una formación higroturbosa de origen periglacial situada en el término municipal de Rascafría (Valle del Lozoya, Madrid). El objetivo principal de este trabajo es reconstruir la evolución de la vegetación en el área durante el Holoceno Reciente. Los resultados obtenidos reflejan la existencia de un paisaje vegetal dominado por el estrato herbáceo, constituido fundamentalmente por Cichorioideae, Asteraceae, Chenopodiaceae, Poaceae y Plantago lanceolata. El grupo arbustivo (Erica arborea, Rosaceae, Juniperus y Cistaceae) tiene un papel poco importante en la vegetación; la masa forestal de Pinus sylvestris y en menor proporción P. pinaster y Quercus, junto a presencias de Betula, y Corylus, es poco representativa a lo largo del perfil, excepto hacia el techo de la secuencia, donde muestra un fuerte y progresivo aumento. De los microfósiles no polínicos destacamos la presencia de Pseudoschizaea circula y Glomus, que puede relacionarse con los procesos erosivos in situ favorecidos por fenómenos de sobrepastoreo. Esta información pone de manifiesto la presencia de un paisaje mediterráneo abierto y antropizado, dominado por zonas de pastizal dedicadas al ganado, según se deduce en el diagrama polínico a través de las proporciones de los componentes nitrófilos de carácter zoógeno y antropozoógeno. La presencia de taxones de ribera (Alnus y Fraxinus) y las variaciones de Cyperaceae, como representante mayoritario de los taxones higro-hidrófilos, definen importantes fluctuaciones en la tasa de humedad. La información proporcionada por los valores del pH (5,4-6,2) y de la conductividad (10-160 μS/cm) del sedimento, constatan los cambios detectados en la vegetación y en los usos del suelo. [ABSTRACT] Here we present palynological analyses carried avow a peaty located near to Rascafría village (Lozoya valley river, Madrid). Vegetation evolution during Late Holocene (940±50 BP) is reconstructed. The results shows a landscape dominated by herbaceous taxa, constituted mainly Cichorioideae, Asteraceae, Chenopodiaceae, Poaceae and Plantago lanceolata. Shrubs such as Erica arborea, Rosaceae, Juniperus and Cistaceae have certain role in the vegetation. Woodlands with Pinus sylvestris, P. pinaster and Quercus, Corylus and Betula are also noticeable throushout the sequence. Non-pollen palynomorphs like Pseudoschizaea circula and Glomus are used to infer the importance of erosive processes in situ. This information shows an open mediterranean landscape, due mainly to human activities, and changes in peatbog trophic condition. Changes in values of Alnus, Fraxinus and Cyperaceae are used to detected humid changes in the area. The information provided by pH (5,4-6,2) and sediment conductivity (10-160 μS/cm) serves to assess vegetation and land uses changes

Reconstrucción paleoambiental y paleoclímática en el entorno del valle del Lozoya: valoración del impacto humano

Se presentan los datos palinológicos, procedentes de un testigo obtenido en el depósito higroturboso RAS, situado en el término municipal de Rascafría (Valle del Lozoya, Madrid), y cuya formación es posterior a los 2.455±35 BP (670-410 BC). Los resultados obtenidos se explican como consecuencia de la interacción del clima y del hombre en el área de estudio. Se trata de un paisaje vegetal abierto, dominado por herbáceas tipo Cichorioideae, Asteraceae, Chenopodiaceae, Poaceae y Plantago lanceolata, acompañado de un pobre cortejo arbustivo (Erica arborea, Rosaceae, Juniperus y Cistaceae) y arbóreo (Pinus sylvestris, en menor proporción P. pinaster y Quercus, y algunas presencias de Betula, y Corylus). De los microfósiles no polínicos destacan Pseudoschizaea circula y Glomus, relacionados con procesos erosivos in situ favorecidos por fenómenos de sobrepastoreo así como los que definen las condiciones tróficas de la turbera. Esta información pone de manifiesto la presencia de un paisaje de carácter mediterráneo, abierto y antropizado, dominado por zonas de pastizal dedicadas al ganado, según se deduce en el diagrama polínico a través de las proporciones de los componentes nitrófilos de carácter zoógeno y antropozoógeno. La presencia de taxones de ribera (Alnus y Fraxinus) y las variaciones de Cyperaceae, representante mayoritario de los taxones higro-hidrófilos, se infieren fluctuaciones en la tasa de humedad. La información proporcionada por los valores de MS (3-12), del pH (5,4-6,2) y de la conductividad (10-160 μS/cm) del sedimento, constatan los cambios detectados en la vegetación y en los usos del suelo

3D printing as an enabling technology to implement maritime plastic Circular Economy

CircularSeas European Project, as part of the European Union Circular Economy [1], aims at promoting the Green Economy by encouraging the development of green products, parts and components by Maritime Industries. The strategy is a combination of Circular Economy principles, with the use of ocean plastic waste for developing new greener materials, and the uptake of advanced manufacturing technology, 3D printing, flexible enough to adapt to the manufacturing conditions for new eco-innovative small and medium parts and components. The paper presents the ongoing research in the project about strategies to introduce Circular Economy in the maritime sector from plastic wastes. This first prospective phase is focused on a series of interviews with each node stakeholders. The paper presents the survey results, together with the challenges to be faced for the implementation of Circular Economy in that specific scenario, despite the -apriori- short term low-profit disadvantages